Adaptable platform for loading and unloading railway cars

ABSTRACT

An apparatus that provides selectively deployable worker access with fall protection to at least a portion of the top of a container disposed above the ground. A gangway and its associated fall protection cage are selectively deployable from an elevated platform over the top of the container. The gangway and its associated cage are slidably connected to the platform via a track carried along the side of the platform.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE INVENTION

The subject matter disclosed herein generally involves elevatedplatforms for accessing the tops of rolling stock for purposes ofloading and unloading same, and particularly fall protection equipmentprovided for such elevated platforms.

BACKGROUND OF THE INVENTION

Long strings of railway tank cars are often pulled alongside of elevatedplatforms for the purpose of loading or unloading the contents of thetanks. These car strings usually are left coupled together, and the topsof the tanks carried by the cars generally need to be accessed byworkers. This worker access typically is effected via a fold-down rampor gangway. In accessing the tops of rolling stock (tank trucks, tankrailroad cars, etc.), a gangway is lowered from the elevated platform toallow workers to move cargo between the platform and the top of therolling stock. These gangways include cantilevers that usually carry aprotective enclosure (aka cage) added to the outboard end to providefall protection while the worker is on top of the rolling stock.Examples of these gangways are disclosed in U.S. Pat. Nos. 4,679,657;5,042,612; 5,392,878; 7,140,467; 7,216,741 and 8,015,647, thedisclosures of which being hereby incorporated herein for all purposesby this reference.

Because of variations in the lengths of railway tank cars, variations inthe configurations of the tops of railway tank cars and operator errorin positioning the railway tank cars relative to the platform, thegangways often are mounted on tracks that enable the gangway to slidealong the length of the platform and thereby assume different positionswith respect to the tops of the railway tank cars. An example of atrack-mounted gangway is disclosed in U.S. Patent ApplicationPublication No. 2012-0045274, the disclosure of which being herebyincorporated herein for all purposes by this reference.

Depending on how the string of cars is spotted, the length of trackrequired to position the gangways along the length of the elevatedplatform can become quite large. The string of railway transport cars isusually spotted from one end of the string of cars or from the middle ofthe string of cars. The farther the car is from the spotting origin, thelonger the length of track that the gangway must traverse in order tobecome properly positioned to allow the worker to access the top of thetank.

A self-closing gate provides access to the gangway when the gangway ismoved opposite the opening to the car. Currently, side rails with thegates are bolted or welded on at specific locations of the elevatedplatform based on current anticipated needs. However, changes in lengthsof cars and car configurations can result in additional track beingneeded than what was originally allowed for. Additionally, the relativelocations of the self-closing gates and the fixed sections of side railon each side of the platform may need to be changed in order toaccommodate the different lengths of cars and different carconfigurations.

Emergency ladders often are used on these long platforms, and eachemergency ladder is provided with its own self-closing gate that in turnprovides access to the ladder from the elevated platform. Thus, toaccommodate the different lengths of cars and different carconfigurations, the relative locations of the emergency ladder and itsassociated self-closing gate also may need to be changed so that it doesnot block movement of the gangway along the track in the platform.

If changed circumstances require reconfiguring the locations of eachgangway and its self-closing gate as well as any emergency ladders andassociated self-closing gate along the length of the elevated loadingplatform, effecting these changes poses problems of disassembly andre-assembly and the time and man-hours associated with completing thesetasks.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects and advantages of the invention are set forth below in thefollowing description, or may be obvious from the description, or may belearned through practice of embodiments of the invention. Those ofordinary skill in the art will better appreciate the features andaspects of such embodiments, and others, upon review of thespecification. A full and enabling disclosure of the present invention,including the best mode thereof to one skilled in the art, is set forthmore particularly in this specification, including reference to theaccompanying figures, in which:

FIG. 1 schematically presents a perspective view of an embodiment of asystem of interchangeably deployable, modular rails and gates for anelevated platform for worker access to the tops of tanks carried byrailcars.

FIG. 2 schematically presents a perspective view of an alternativearrangement of an embodiment of a system of interchangeably deployable,modular rails and gates for an elevated platform for worker access tothe tops of tanks carried by railcars with an alternative disposition ofgates shown in dashed outline.

FIG. 3 is a top plan view of an embodiment of an elevated platform withtrack mounted, modular gangways and gates for worker access to the topsof tanks (shown in dashed outline) carried by railcars.

FIG. 4 is a side plan view of an elevated platform with track mounted,modular gangways and gates for worker access to the tops of tankscarried by railcars disposed in alignment with a selectively retractableguide railings for an emergency ladder.

FIG. 5 is a side plan view taken in FIG. 8 along the sight lines of thearrows designated 5-5 of an elevated platform for worker access to thetops of tanks carried by railcars and with selectively retractable guiderailings for an emergency ladder schematically shown in a deployed andretracted (dashed line) configuration.

FIG. 6 is a front plan view taken in FIG. 8 along the sight lines of thearrows designated 6-6 of an embodiment of components of an elevatedplatform for worker access to the tops of tanks carried by railcars withan emergency ladder and gate.

FIG. 7 schematically presents a view taken in FIG. 3 along the sightlines of the arrows designated 7-7 of an embodiment of components of anelevated worker platform with track mounted, modular gangways and gatesfor worker access to the tops of tanks (shown in dashed line) carried byrailcars.

FIG. 8 is a top plan view similar to that taken in FIG. 3 of componentsof an embodiment of an elevated platform with modular side railings andgates for worker access to the tops of tanks (not shown) carried byrailcars.

FIG. 9 is a front plan view of an embodiment of components of anelevated platform with modular side railings and gates for worker accessto the tops of tanks (not shown) carried by railcars.

FIG. 10 is an isometric view of embodiments of components of an elevatedplatform for worker access to the tops of tanks carried by railcars withan emergency ladder and gate.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate at least one presently preferredembodiment of the invention as well as some alternative embodiments.These drawings, together with the written description, serve to explainthe principles of the invention but by no means are intended to beexhaustive of all of the possible manifestations of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to present embodiments of theinvention, one or more examples of which are illustrated in theaccompanying drawings. The detailed description uses numerical andletter designations to refer to features in the drawings. Like orsimilar designations in the drawings and description have been used torefer to like or similar parts of the invention.

Each example is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that modifications and variations can be made in thepresent invention without departing from the scope or spirit thereof.For instance, features illustrated or described as part of oneembodiment may be used on another embodiment to yield a still furtherembodiment. Thus, it is intended that the present invention covers suchmodifications and variations as come within the scope of the appendedclaims and their equivalents.

It is to be understood that the ranges and limits mentioned hereininclude all sub-ranges located within the prescribed limits, inclusiveof the limits themselves unless otherwise stated. For instance, a rangefrom 100 to 200 also includes all possible sub-ranges, examples of whichare from 100 to 150, 170 to 190, 153 to 162, 145.3 to 149.6, and 187 to200. Further, a limit of up to 7 also includes a limit of up to 5, up to3, and up to 4.5, as well as all sub-ranges within the limit, such asfrom about 0 to 5, which includes 0 and includes 5 and from 5.2 to 7,which includes 5.2 and includes 7.

The longitudinal direction extends along the length of a structure, andthe length of an elongated structure is the longest dimension of thestructure. The transverse direction extends perpendicular to thelongitudinal direction along the width of a structure, and the width ofan elongated structure is the shorter orthogonal dimension of thestructure. The vertical direction typically is the orthogonal directionthat is normal to both the transverse direction and the longitudinaldirection and typically is parallel to the direction in which the forceof gravity would tend to operate when the apparatus in question is beingused for its intended purpose.

When one structure is selectively attached to another structure orselectively connected to another structure, it means that the twostructures are attached or connected at the option of the user and thuscan be separated from one another at the option of the user withoutdamaging the two structures and without damaging the fastening elementsthat were used to effect the connection or attachment between the twostructures. Similarly, when one structure is detachably attached toanother structure or detachably connected to another structure, it meansthat the two structures are attached or connected at the option of theuser and thus can be separated from one another at the option of theuser without damaging the two structures and without damaging thefastening elements that were used to effect the connection or attachmentbetween the two structures. Typically, in both of these cases, the twostructures can be reused repeatedly, and the fastening elements can bereused repeatedly as well.

An embodiment of the apparatus 20 of present invention that includes anelevated platform 22 for worker access to the tops 13 a of tanks 13carried by railcars in accordance with the present invention is depictedfrom different vantage points in each of FIGS. 3 and 7-9 for example.More detailed aspects of embodiments of various components ofembodiments of the elevated platform 22 are shown in FIGS. 1, 2, 4-6 and10 for example. As explained more fully below, because of the modularnature of some of these various components, different combinations ofthem can be made within the scope of the present invention so that oneembodiment of one component may be combined with another embodiment ofthe same or a different component to yield a still further embodiment ofthe present invention.

As noted above, some embodiments of the apparatus 20 of the presentinvention may include an elevated platform, which is schematicallyrepresented by the element designated by the numeral 22 in FIG. 3 forexample. As shown in FIGS. 3 and 7-9 for example, the apparatus 20desirably includes an elevated platform 22 that extends in alongitudinal direction and is defined in part by a deck 22 a. As shownfrom a head on view in FIG. 7 and from a side view in FIG. 9, the deck22 a of the elevated platform 22 typically is supported and suspendedabove the ground by a plurality of rigid legs 22 b that are theelongated, underlie the platform 22 and carry same. These rigid legs 22b desirably may be formed from steel girders for example and areconventional in the art.

Some components of embodiments of the apparatus 20 of the presentinvention can be retrofitted to platforms 22 that already exist.However, unlike conventional elevated platforms in which the fixedrailings and swing gates are welded permanently to the platform, theapparatus of the present invention permits non-destructive disassemblyand detachable reassembly of these elements to the platform in order toaccommodate repositioning of the swinging gates and the fixed railingsin different arrangements and so permit worker access to different railcar configurations (especially regards the relative positioning of theloading hatches for the rail cars) as well as different rail trainconfigurations (different rail cars connected successively in adifferent order in the train for example).

As schematically shown in FIGS. 3 and 8 for example, the deck desirablyhas a pair of longitudinally extending sides that are separated apartfrom one another in the transverse direction, which is the directionthat is normal to the virtual centerline 21 shown in dashed line in FIG.8 for example. As shown in FIG. 8 for example, each side of the deck 22a desirably is disposed to a respective opposite side of a virtuallongitudinal centerline 21 that extends down the length of the platform22 and is oriented normal to the transverse direction. As shown in FIGS.8 and 10 for example, the deck 22 a desirably is formed by steel deckingthat is rated to support the types of loads that are anticipated wherethe apparatus 20 will be installed.

As schematically shown in FIGS. 3 and 8 for example, the apparatus 20desirably includes a pair of longitudinally extending stringers 23 thatform the opposite sides of the platform. As shown in FIG. 3 for example,a first stringer 23 is disposed along one side of the deck, and a secondstringer 23 is disposed along the opposite side of the deck. FIGS. 1 and2 illustrate an individual section of a modified metal I-bar that formsa section of an individual longitudinally extending stringer 23. Asshown in FIG. 1 for example, each stringer 23 defines an upper flange 23a that extends along the length of the stringer 23 and extends generallyin the transverse direction. Moreover, each stringer 23 further definesa lower flange 23 b that is spaced vertically apart from the upperflange 23 a. The lower flange 23 b extends along the length of the firststringer 23 and also extends in the transverse direction. As shown inFIG. 10 for example, the upper flange 23 a of each stringer 23 defines adepending lip 23 c that extends along the length of the stringer 23 andextends generally in the vertical direction from the upper flange 23 a ashort distance toward the lower flange 23 b to form one side of athree-sided channel 23 d. As shown in FIGS. 1, 2 and 10 for example, theupper and lower flanges 23 a, 23 b of each stringer 23 form part of atrackway 24 that includes the channel 23 d and extends along the lengthof each respective stringer 23 and thus extends longitudinally down eachside of the deck 22 a.

As embodied herein and indicated generally by the numeral 30 in each ofFIGS. 3, 4 and 7 for example, the apparatus 20 desirably includes atleast a first gangway 30, and desirably a plurality of gangways 30 suchas shown in FIGS. 3 and 7 for example. As shown in FIGS. 4 and 7 forexample, each gangway 30 has an inboard end 30 a that is configured tobe constrained within the trackway 24 of one of the stringers 23. Asshown in FIG. 7 for example, the inboard end 30 a of each gangway 30 ispivotally connected to the platform 22 and configured to slidably movealong and generally within the trackway 24 of one of the stringers 23.The manner of effecting the configuration of the inboard end 30 a of thegangway 30 so as to be slidable within the constraints of the firsttrackway 24 is conventional and disclosed for example in commonly ownedU.S. Patent Application Publication No. 2012-0045274, the disclosure ofwhich being hereby incorporated herein for all purposes by thisreference.

As shown in FIGS. 4 and 7 for example, each gangway 30 also includes anoutboard end 30 b that is spaced apart from and disposed generallyopposite the inboard end 30 a in a transverse direction. As isconventional and shown in FIG. 7 for example, a fall protection cage 35can be provided and has an inboard end 35 a connected to the outboardend 30 b of the gangway 30. Moreover, as shown in FIG. 4 for example,each gangway 30 is configured for pivotal movement of the outboard end30 b with respect to the inboard end 30 a. FIG. 4 illustrates theoperational mode of the apparatus 20 in which the gangway 30 iscompletely retracted as the gangway 30 is slidably moving within thetrackway 24 down the length thereof, such movement being in thedirection into and out of the view shown in FIG. 4 for example.Conversely, FIG. 7 illustrates the operational mode in which theapparatus 20 deploys a first gangway 30 from one side of the platform 22and a second gangway 30 from the opposite side of the platform 22 in thefully extended mode so that each gangway 30 reaches the respective top13 a of a tank 13 that is to be accessed by workers walking from theplatform 22 onto the respective gangway 30 and onto the top 13 a of therespective tank 13, which is shown in phantom by the chain dashedoutline. Moreover, as schematically shown in FIG. 7 for example, theoutboard end 35 b of each fall protection cage 35 is deployed over thework area on the top 13 a of the tank 13. Also shown in chain dashedoutline in FIG. 7 are the curved ladders 14 that provide access fromeach opposite side of the tank 13, the safety railing 15 at the top ofthe ladders 14 carried by the tank 13, and the service hatch 16 fromwhich the cargo will be extracted from the tank 13 or loaded into thetank 13, as the case may be.

The details of the gangway 30 are varied and conventional and can belearned for example from the disclosures in U.S. Patent ApplicationPublication Nos. 2012-0045274 and 2012-0042458, the disclosure of eachof which being hereby incorporated herein for all purposes by thisreference. As embodied herein and shown in FIG. 3 for example, the widthof the gangway 30 is defined between a first side 31 of the gangway 30and a second side 32 of the gangway 30 opposing the first side 31 of thegangway 30. As shown in FIG. 7 for example, the gangway 30 provides awalking surface 33 upon which workers can walk from the deck 22 a of theplatform 22 onto the top 13 a of the tank 13. The operative orientationof the gangways 30 is shown in FIGS. 3 and 7 for example. As shown inFIG. 7 for example, the walking surface 33 extends generallyhorizontally in a transverse direction from the platform 22 to the top13 a of the tank 13 that is to be accessed by workers for inspection,loading or unloading. In its stored orientation shown in FIG. 4 forexample, the gangway 30 and its walking surface 33 is pivoted above theplatform 22 and disposed generally at a right angle with respect to thedeck 22 a of the platform 22.

As shown in FIGS. 4 and 7 for example, the walking surface 33 of thegangway 30 typically is bounded on each respective opposite side by agangway railing that is indicated generally by the numeral 34. Thegangway railing 34 desirably is configured so that it can fold andcollapse onto itself to permit the gangway 30 at the user's option to beraised above the normal horizontal walking plane and lowered to disposethe walking surface 33 of the gangway 30 in a position suited forworkers to move between the top 13 a of the tank 13 and the deck 22 a ofthe platform 22.

In accordance with the present invention, as shown in FIGS. 1, 2 and 10for example, at least the upper flange of each stringer 23 defines aplurality of bolt openings 25. The spatial arrangement of the boltopenings 25 in each stringer 23 on each opposite side of the platform 22desirably is the same, but can be different in some embodiments.Moreover, these arrangements of bolt openings 25 can be done in pairs ortriplets or any other multiple grouping instead of as a single boltopening 25, depending on the number of bolts needed to detachably anchoreach of the modules of the platform railings and/or the gate modules 50.In the examples given below, groupings in pairs of bolt openings 25 willbe used to explain this aspect of the present invention.

In the embodiment shown in FIGS. 1, 2 and 10, each grouping of boltopenings 25 includes two side-by-side bolt openings 25 wherein each boltopening 25 is defined vertically through the upper flange 23 a of thestringer 23. In this case, as schematically shown in FIG. 10 forexample, the magnitude of the linear distance in the longitudinaldirection between each pair of side-by-side bolt openings 25 of eachgrouping of bolt openings 25 is a gap that is generally designated bythe upper case letter G. Moreover, this gap G between the bolt openings25 in each grouping of bolt openings 25 desirably will be the samethroughout each such grouping of bolt openings 25 of the stringer 23. Aconvenient reference point for measuring the distance that defines thegap G in the longitudinal direction between the pair of bolt openings 25in a particular group of bolt openings 25 is the center of each boltopening 25. However, whether the reference point for the measures of thegap G is chosen as the point equidistant between the bolt openings 25 ofeach grouping or a different reference point doesn't matter so long asthe chosen reference point remains consistent. Additionally, while thereare two side-by-side bolt openings 25 in the embodiment of the groupingof bolt openings 25 depicted in the drawings, a different number of boltopenings 25 in each grouping of bolt openings 25 is contemplated andcould be for example three bolt openings 25 in each grouping or forexample just a single bolt opening 25 in each grouping. Naturally, inthe case of the single bolt opening 25 in the grouping of bolt openings25, no gap would exist and G becomes zero and thus would beinapplicable, and the meaning of the term grouping in such an instancewould default to a set with only one member.

In accordance with one embodiment of the present invention, there aretwo types of successive dual groupings of bolt openings 25 definedthrough the upper flange 23 a of each stringer 23. Each type ofsuccessive dual groupings of bolt openings 25 is characterized by adifferent standard separation distance measured in the longitudinaldirection. As schematically shown in FIG. 1 for example, one of the twotypes of successive dual groupings of bolt openings 25 defined in atleast the upper flange 23 a of the first stringer 23 is characterized bya relatively smaller spacing measured in the longitudinal directionbetween any successive groupings of bolt openings 25, and thisrelatively smaller spacing distance is denominated a first spacing anddesignated by the alphanumeric S1. Moreover, as shown in FIG. 1 each ofthese smaller first spacings S1 has the same magnitude. Additionally, asschematically shown in FIG. 1 for example, the other of the two types ofsuccessive dual groupings of bolt openings 25 defined in at least theupper flange 23 a of the first stringer 23 is characterized by arelatively larger spacing measured in the longitudinal direction betweenany the successive groupings of bolt openings 25, and this relativelylarger spacing distance is denominated a second spacing and designatedby the alphanumeric S2. Moreover, as shown in FIG. 1 each of theselarger second spacings S2 has the same magnitude. It should be notedthat if only a single bolt suffices to anchor the posts of the railingmodules or gate modules 50, then each grouping will be defined by asingle bolt opening 25 that is separated by either the first spacing S1or the second spacing S2.

Thus, as schematically shown in FIG. 1 for example, the distancemeasured in the longitudinal direction between the end groupings of boltopenings 25 of two successive groupings of bolt openings 25 of thesecond type of successive dual groupings of bolt openings 25characterized by the larger second spacing S2 will have a magnitude thatis a third spacing generally designated by the alphanumeric S3 that isequal to two times (twice) the second spacing S2 plus the first spacingS1, which is the separation distance between anchoring points of twoside-by-side modules characterized by the unit spacing S2. In otherwords, 2×S2+S1=S3. Thus, as schematically shown in FIGS. 1 and 2 forexample, the S3 magnitude is equal to a whole number multiple (2 in thecase of FIG. 1) of the S2 magnitude plus the magnitude of the smallerspacing S1 that exists between the two successive groupings of boltopenings 25 that are separated by the larger spacing magnitude S2.

Conventional loading platforms include conventional side railings orfencing as well as swing gates that control worker access between theplatform and the tops 13 a of the tanks 13 for purposes of loading orunloading. Moreover, these conventional railings and swing gates arepermanently welded to the conventional platform. However, instead ofbeing permanently welded along the sides of the deck forming theelevated platform as in these conventional loading platforms, theplatform railings in accordance with the present invention are broken upinto modules of one or more standard lengths, and these railing modulesin accordance with the apparatus 20 of the present invention areselectively, detachably bolted to the stringers 23 that form part of thetrackways 24 disposed along the sides of the deck 22 a of the platform22 of the apparatus 21 of the present invention. Similarly, inaccordance with the present invention, each gate module 50 (describedmore fully hereafter) that includes a barrier 52 pivotally connected toa gate post 51 desirably is configured with a longitudinal dimensionthat permits a degree of interchangeability with embodiments of themodules of the platform railings 40, 44 (described more fullyhereafter). Moreover, in accordance with the present invention,embodiments of the modules of the platform railings 40, 44 areconfigured so that the longitudinal dimension of the largest module ofthe platform railings 40 is some whole number multiple of thelongitudinal dimension of the smallest of the modules of platformrailings 40 and/or the gate module 50 plus the separation distance S1between the anchoring points of the side-by-side smallest modules.

As schematically shown in FIGS. 1 and 2 for example, any twoside-by-side unit modules, be they embodiments of platform railingmodules 44 or embodiments of the gate modules 50 or one platform railingmodule 44 adjacent to an embodiment of one gate module 50, can beinterchanged with one of the larger platform railing modules 40 of theS3 magnitude measured in the longitudinal dimension. Moreover, it isthis uniformity of the magnitudes of the spacings between the boltopenings 25 and the arrangement of the groupings of bolt openings 25that permits a modular approach to the detachable attachment of thevarious fall protection components, which are described in more detailhereafter and that include for example the platform railing modules 40,44 and embodiments of the gate modules 50.

As schematically shown in FIG. 1 for example, the apparatus 20 desirablyincludes at least a first platform railing module 40 that defines atleast a first end post 41 and a second end post 42 that is spaced apartin the longitudinal direction from the first end post 41. Each of theend posts 41, 42 extends in a vertical direction and desirably can beconnected by one or more horizontally elongated connecting rails 45.Each end post 41, 42 also has a vertically lower end that defines a footflange 43. Each foot flange 43 defines a grouping of bolt openings 26,and these bolt openings 26 in the foot flange 43 are sized and spacedapart from one another in the same manner as each grouping of boltopenings 25 defined through the stringer 23. Moreover, the magnitude ofthe spacing in the longitudinal direction between the bolt openings 26of each grouping of each foot flange 43 of each platform railing module40 is the same first spacing G described above in relation each groupingof bolt openings 25 defined through the stringers 23. Additionally, themagnitude of the spacing in the longitudinal direction between thegrouping of bolt openings 26 of the foot flange 43 of the first end post41 and the grouping of bolt openings 26 of the foot flange 43 of thesecond end post 42 is a whole number multiple of the second spacing S2plus the first spacing S1. For the platform railing module 40 in theembodiment shown in FIG. 1, that whole number multiplier is the number2. Moreover, as shown in FIG. 2 for example, for a second type ofplatform railing module 44 that differs from the first platform railingmodule 40 by the different lengths of the connecting rails 45, themagnitude of the spacing in the longitudinal direction between thegrouping of bolt openings 26 of the foot flange 43 of the first end post41 and the grouping of the bolt openings 26 of the foot flange 43 of thesecond end post 42 desirably can be equal to the magnitude of the secondspacing S2 alone. Thus, allowing for the longitudinal distances betweeneach of the end posts 41, 42 of each type of platform railing module 40,44, the bolt openings 26 in the foot flanges 43 of each platform railingmodule 40, 44, will align with and correspond to the bolt openings 25 inthe upper flange 23 a of the stringer 23.

As shown in FIGS. 1 and 2 for example, pluralities of threaded bolts 27and mating threaded nuts 28 are provided. A threaded bolt 27 isselectively received through one of the respective bolt openings 26 ofthe foot flange 43 of one of the end posts 41 or 42 as well as throughan aligned bolt opening 25 of the upper flange 23 a of the stringer 23so as to selectively attach that respective end post 41 or 42 of theplatform railing module 40 or 44 via a respective threaded nut 28 thatis tightened on the end of the respective threaded bolt 27. Similarly, asecond threaded bolt 27 is selectively received through a respectivebolt opening 26 of the foot flange 43 of the other end post 41 or 42 ofthe platform railing module 40 or 44 and successively through an alignedrespective bolt opening 25 of the upper flange 23 a of the stringer 23to selectively attach the opposite end post 41 or 42 of the platformrailing module 40 or 44 via a second threaded nut 28 that is tightenedon the end of the second threaded bolt 27. In this way, each platformrailing module 40 or 44 can be detachably connected to the platform 22via the threaded nuts 28 attached to the threaded bolts 27. Moreover,removal of each platform railing module 40 or 44 is easily achieved byundoing the bolts 27 and nuts 28 without damaging either the platform22, the platform railing module 40 or 44 or the bolts 27 and nuts 28.Thus, use of the apparatus 20 of the present invention easilyaccommodates different rail car configurations and different trainconfigurations pulled up alongside of the platform 22 for loading orunloading.

As shown in FIGS. 6 and 8-10 for example, the apparatus furtherdesirably can include a plurality of swing gate modules 50 that aredetachably connected to the platform 22. As shown in FIGS. 1, 2 and 10in particular for example, each gate module 50 is detachably connectedto the upper flange 23 a of the stringer 23 of the platform 22. Asschematically shown in FIG. 3 for example, gate modules 50 desirably areconfigured and disposed so as to selectively control ingress and egressof workers between the deck 22 a and one of the gangways 30.Alternatively, as explained more fully below, gate modules 50 alsodesirably are configured and disposed so as to selectively controlingress and egress of workers between the deck 22 a and one of theemergency egress ladders 17 (e.g., FIGS. 6 and 10).

As shown in FIGS. 1, 2 and 10 for example, each gate module 50 desirablyincludes at least one gate post 51 and a gate barrier 52 that ispivotally connected to the gate post 51. Moreover, as shown in FIG. 10for example, the pivotal connection between the barrier 52 and the gatepost 51 desirably is effected by a spring-biased hinge connection 53that biases the position of the barrier 52 in the closed position suchas shown in FIGS. 1 and 2 for example. In the closed position, the gatemodule 50 desirably has its barrier 52 disposed so as to block passageof workers between the deck 22 a and a gangway 30 or an emergency egressladder 17 (e.g., FIGS. 6 and 10). In the closed position, the gatemodule 50 desirably has its barrier 52 disposed in alignment with theadjacent platform railing module 40 or 44. As shown in FIGS. 1, 2 and 10for example, the barrier 52 of the gate module 50 desirably is providedwith a stop flange 54 that prevents the spring-biased hinge connection53 from moving the barrier past alignment with the adjacent platformrailing module 40 or 44. However, as schematically shown in FIGS. 3, 8and 10 for example, each gate module 50 desirably is configured so thatthe spring-biased hinge connection 53 permits the worker to pivot thebarrier 52 manually in a manner to swing the barrier 52 inwardly towardthe longitudinal centerline 21 of the deck 22 a to open up workerpassage between the deck 22 a and a gangway 30 or an emergency egressladder 17 (e.g., FIGS. 6 and 10).

As shown schematically in FIG. 1 for example, the gate post 51 of eachswing gate module 50 extends in a vertical direction and has avertically lower end that defines a foot flange 55. In an alternativeembodiment shown in FIG. 10 for example, a single post serves as boththe gate post 51 of the swing gate module 50 and an end post 42 of anadjacent platform railing module 44, and thus the gate post 51 and theend 42 post share a foot flange 43, 55. In each case, the foot flange43, 55 defines a group of bolt openings 26, 56. The magnitude of thespacing in the longitudinal direction between the bolt openings 56 ofthe foot flange 55 of the gate post 51 is the same as the magnitude ofthe gap G in the foot flange 43 of the end posts 41, 42 of the platformrailing module 40, 44 and thus the same as the gap G between the boltopenings 25 of the upper flange 23 a of the stringer 23.

As schematically shown in FIG. 1 for example, the longitudinal extent ofsome embodiments of the gate module 50 desirably is one half of thelongitudinal extent of one embodiment of the larger of the fixed railingmodules 40. As schematically shown in FIGS. 2, 6 and 9 for example, thelongitudinal dimension of some embodiments of the gate module 50 plusthe longitudinal dimension of some embodiments of the smaller of thefixed railing modules 44 equals the longitudinal dimension of the largerof the fixed railing modules 40. Accordingly, some embodiments of eachgate module 50 configured so that when aligned in succession with one ofthe smaller of the fixed railing modules 44, these two components of theapparatus 20 are be interchangeably detachably connected to upper flangeof the stringer 23 with the larger of the fixed railing modules 40.Similarly, some embodiments of the gate modules 50 are configured sothat when two of these embodiments of the gate modules 50 are aligned insuccession they are interchangeably detachably connected to the upperflange 23 a of the stringer 23 with the larger of the fixed railingmodules 40.

As shown in FIGS. 4-6 and 10 for example, conventional platforms may beprovided with one or more emergency egress ladders 17 that are rigidlyfixed to the platform 22. As shown in FIG. 6 for example, each suchemergency egress ladder 17 includes a plurality of rungs 18 disposedhorizontally between a pair of opposing side rails 19 and successivelyin a vertical direction downwardly from the platform 22 to permitworkers to escape from the platform 22 in an emergency situation. Asshown in FIG. 10 for example, the top rung 18 a of the emergency egressladder 17 is disposed closest to the platform 22 among the plurality ofrungs 18. The top rung 18 a and the uppermost ends 19 a of the siderails 19 of the fixed emergency ladder 17 are disposed beneath theplatform 22 so as not to interfere with the passage of the gangway 30sliding along the trackway 24 up and down the length of the platform 22.It is conventional therefore to provide a gate at the location of eachof these fixed emergency egress ladders 17, and this gate is biased inthe closed position that blocks passage from the deck 22 a of theplatform 22 to the top of the emergency ladder 17. Thus, in order todescend the emergency ladder 17, workers must open the gate disposed atthe top of the ladder 17 and turn 180 degrees before stepping backwardswith one foot to descend the ladder 17. However, in an emergencysituation, each worker who is rushing to descend the fixed emergencyegress ladder 17 must take care in assuring that the worker's first stepmakes contact with the upper rung 18 a of the emergency ladder 17.Moreover, this first step must be taken in a direction that not only isdescending from the platform 22 but also spaced apart in the transversedirection from the platform 22, thereby increasing the chances of amisstep, especially during an emergency in which the workers are in ahurry to leave the deck 22 a of the platform 22 and descend the ladder17 to reach the safety on the ground.

In accordance with the present invention as schematically shown in FIGS.4-6 and 10 for example, embodiments of the apparatus desirably caninclude one or more ladder extension modules 60. As shown in FIG. 10 forexample, each ladder extension module 60 is configured to be disposed ingeneral alignment with the top of the emergency ladder 17 that extendsvertically beneath the platform 22. As shown in FIGS. 4-6 for example,each ladder extension module 60 desirably is configured so as to bedetachably connected to the platform 22. As shown in FIG. 10 forexample, each ladder extension module 60 is desirably configured so asto be detachably connected to the upper flange 23 a of the stringer 23on one side of the deck 22 a. However, a ladder extension module 60desirably can be retrofitted to a pre-installed swing gate that isdisposed to provide access to a fixed emergency egress ladder 17.

Moreover, as schematically shown in FIG. 10 for example, thelongitudinal dimension of one embodiment of a ladder extension module 60desirably is the same as the longitudinal dimension of three of thesmaller of the fixed railing modules 44 or the longitudinal dimension ofthree of one of embodiments of the gate modules 50. Accordingly, oneembodiment of a ladder extension module 60 is configured to beinterchangeably detachably connected to the upper flange 23 a of thestringer 23 in place of two of the smaller of the fixed railing modules44 and one of one embodiment of the gate modules 50 in succession.Alternatively, one embodiment of a ladder extension module 60 isconfigured to be interchangeably detachably connected to the upperflange 23 a of the stringer 23 in place of one of the larger of thefixed railing modules 40 and one of one embodiment of the gate modules50 in succession.

As shown in FIG. 10 for example, each ladder extension module 60desirably includes a pair of sidebars 61, 62, and a first sidebar 61 islongitudinally spaced apart from a second sidebar 62 that is disposedgenerally in parallel with the first sidebar 61. Furthermore, as shownin FIGS. 5 and 10 for example, each ladder extension module 60 desirablyincludes for each sidebar 61, 62, at least a first linkage 63 anddesirably a plurality of linkages 63. As shown in FIG. 10 for example,each linkage 63 has one end pivotally connected to the sidebar 61 or 62and a second end pivotally connected to the gate post 51 for the gate,whether it is the gate post 51 with the spring biased hinge or the gatepost 41 of a railing module 40 or 44 that is disposed longitudinallyspaced apart from the gate post 51 with the spring biased hinge 53.

As schematically shown in FIG. 5 for example, the pivoting movement ofthe sidebars 61 with respect to the linkages 63 renders the ladderextension module 60 selectively deployable between an extended mode anda retracted mode. In the view of FIG. 5, the retracted mode is indicatedby the dashed outline, while the extended mode is indicated by the solidoutline of the first sidebar 61 that is visible in the view of FIG. 5.When the ladder extension module 60 is deployed in the extended mode asschematically shown in FIGS. 5, 8 and 10 for example, the sidebars 61,62 are disposed in the extended position. As schematically shown in FIG.5 for example, the sidebars 61, 62 are disposed in a retracted positionand folded against the gate post 51 or end post 41 or 42 (as the casemay be) when the ladder extension module 60 is disposed in the retractedmode (dashed outline in FIG. 5). As shown in FIGS. 5 and 10 for example,in the extended mode, the respective sidebar 61 or 62 of the ladderextension module 60 is disposed spaced apart from the associated gatepost 51, 41 or 42 by a distance that is substantially comparable to thelength of one of the respective linkages 63. Moreover, as schematicallyshown in FIG. 4, when the ladder extension module 60 is disposed in theretracted mode, the sidebars 61, 62 are thus disposed in their retractedpositions wherein each sidebar 61, 62 rests against the respectiveconnected gate post 51 or end post 41 or 42. In the retracted modeschematically shown in FIG. 4, the ladder extension module 60 isconfigured so as to permit the gangway 30 to bypass the ladder extensionmodule 60 as the gangway 30 slides longitudinally along the trackway 24.

As shown in FIG. 10 for example, each ladder extension module 60includes a ladder rung 64 that is connected between the pair of sidebars61, 62, and accordingly this ladder rung 64 is selectively deployablebetween an extended mode and a retracted mode along with the sidebars61, 62. In retracted mode, the ladder rung 64 of each ladder extensionmodule 60 is disposed close enough to the longitudinal centerline 21 ofthe deck 22 a so as to allow each gangway 30 to bypass the ladder rung64 as the gangway 30 moves slidably along the trackway 24.

When the ladder extension module 60 is deployed in the extended mode,the sidebars 61, 62 are disposed relatively farther away from thelongitudinal centerline 21 of the deck 22 a. As shown in FIG. 10 forexample, when the ladder extension module 60 is deployed in the extendedmode, the sidebars 61, 62 assume a disposition so that they aresubstantially vertically aligned with the upper ends 19 a of the fixedemergency ladder 17. Moreover, as shown in FIG. 10 for example, when theladder extension module 60 is deployed in the extended mode, the ladderrung 64 of the ladder extension module 60 is likewise disposed invertical alignment with the ladder rungs 18 a, 18 b of the fixed ladder17. Additionally, as shown in FIG. 10 for example, when the ladderextension module 60 is deployed in the extended mode, the disposition ofthe ladder rung 64 in the ladder extension module 60 desirably isdisposed so that the vertical distance between the top rung 18 a of thefixed ladder 17 and the rung 64 of the ladder extension module 60 issubstantially the same as the vertical distance that separates at leastthe two uppermost rungs 18 a, 18 b of the fixed ladder 17. The verticaldistance separating the uppermost two rungs 18 a, 18 b of the emergencyegress ladder 17 is deemed to be substantially the same as the verticaldistance between the top rung 18 a of the emergency egress ladder 17 andthe rung 64 of the ladder extension module 60 when the user of same isunlikely to notice any difference in vertical height during descent ofthe emergency ladder 17 via the ladder extension module 60. In this way,when the ladder extension module 60 is deployed in its extended mode,the ladder extension module 60 assumes a configuration that acts as anuninterrupted extension of the fixed emergency ladder 17, both as to theorientation of the sidebars 61, 62 with the side rails 19 of theemergency ladder 17 and the orientation of the ladder extension's rung64 with the rungs 18 of the emergency ladder 17.

Because of these standardized length dimensions of the anchoring pointsof the modules 40, 44, 50, 60 and the commensurately standardizedspacing of the bolt openings 25 along the upper flanges 23 a of thestringers 23 in accordance with one aspect of the present invention, thesame platform railing modules 40, 44, and swinging gate modules 50 canbe selectively detached and moved to different locations along theplatform 22 and positioned in different arrangements with respect to oneanother. Moreover, the same detachably interchangeable advantage issecured through use of the ladder extension module 60 in accordance withthis aspect of the present invention.

While at least one presently preferred embodiment of the invention hasbeen described using specific terms, such description is forillustrative purposes only, and it is to be understood that changes andvariations may be made without departing from the spirit or scope of thefollowing claims. This written description uses examples to disclose theinvention, including the best mode, and also to enable any personskilled in the art to practice the invention, including making and usingany devices or systems and performing any incorporated methods. Thepatentable scope of the invention is defined by the claims, and mayinclude other examples that occur to those skilled in the art. Suchother examples are intended to be within the scope of the claims if theyinclude structural elements that do not differ from the literal languageof the claims, or if they include equivalent structural elements withinsubstantial differences from the literal languages of the claims.

What is claimed is:
 1. An apparatus that provides selectively deployableworker access with fall protection to at least a portion of the top of atank disposed above the ground and carried by a railcar on a railroadtrack, the apparatus comprising: a. an elevated platform extending in alongitudinal direction and defined in part by a deck having a pair oflongitudinally extending sides that are separated apart from one anotherin the transverse direction, each side of the deck being disposed to arespective opposite side of a virtual longitudinal centerline thatextends down the length of the platform and is oriented normal to thetransverse direction; b. a pair of longitudinally extending stringers, afirst stringer disposed along one side of the deck and a second stringerdisposed along the opposite side of the deck, each stringer defining anupper flange extending along the length of the respective stringer andextending in the transverse direction; c. at least the first stringerdefining a lower flange spaced vertically apart from the upper flange,the lower flange extending along the length of the first stringer andextending in the transverse direction, the upper and lower flanges ofthe first stringer forming part of a first trackway extending along thelength of the first stringer; d. a first gangway having an inboard enddisposed between the upper and lower flanges of the first stringer andslidably along the first trackway, the first gangway having an outboardend spaced apart from the inboard end in a transverse direction andconfigured for pivotal movement with respect to the inboard end; e. atleast the upper flange of the first stringer defining a plurality ofgroupings of bolt openings wherein the magnitude of the spacing in thelongitudinal direction between the bolt openings of each group is afirst spacing and the magnitude of the spacing in the longitudinaldirection between any two groups in succession along the length of thefirst stringer is a second spacing; f. a first railing defining at leasta first end post and a second end post spaced apart in the longitudinaldirection from the first end post, each of the end posts extending in avertical direction, each end post having a vertically lower end defininga foot flange, each foot flange defining a group of bolt openingswherein the magnitude of the distance in the longitudinal directionbetween the bolt openings of each group of each foot flange is the gapand wherein the magnitude of the spacing in the longitudinal directionbetween the group of bolt openings of the foot flange of the first endpost and the group of bolt openings of the foot flange of the second endpost is the first spacing; and g. a plurality of threaded bolts and nutswherein a first threaded bolt is selectively received through arespective bolt opening of the foot flange of the first end post and arespective bolt opening of the upper flange of the first stringer toselectively attach the respective first end post of the first railingvia a respective first threaded nut tightened on the end of therespective first threaded bolt and wherein a second threaded bolt isselectively received through a respective bolt opening of the footflange of the second end post and a respective bolt opening of the upperflange of the first stringer to selectively attach the respective secondend post of the first railing via a second threaded nut tightened on theend of the second threaded bolt.
 2. The apparatus of claim 1, furthercomprising a first gate detachably connected to the upper flange of thefirst stringer and configured to swing inwardly toward the longitudinalcenterline of the deck.
 3. The apparatus of claim 2, wherein each of thefirst railing and the first gate is configured so as to beinterchangeably detachably connected to the upper flange of the firststringer.
 4. The apparatus of claim 2, wherein the first gate isdisposed so as to selectively control ingress and egress of workersbetween the deck and the gangway.
 5. The apparatus of claim 2, whereinthe first gate includes a first gate post and a first barrier pivotallyconnected to the first gate post, wherein the first gate post extends ina vertical direction and has a vertically lower end defining a footflange defining a group of bolt openings, wherein the magnitude of thedistance in the longitudinal direction between the bolt openings of thefoot flange of the first gate post is the gap.
 6. The apparatus of claim5, further comprising a first ladder extension detachably connected tothe upper flange of the first stringer and including a pair oflongitudinally spaced apart sidebars, each sidebar configured to bepivotable between an extended position and a retracted position, whereinthe first ladder extension includes a first linkage and a secondlinkage, at least the first linkage having one end pivotally connectedto a first one of the sidebars and a second end pivotally connected tothe first gate post, wherein pivoting movement of the sidebars withrespect to the linkages renders the first ladder extension selectivelydeployable between an extended mode and a retracted mode, wherein in theextended mode the sidebars of the first ladder extension are disposedspaced apart from the first barrier by a distance substantiallycomparable to the length of the first linkage.
 7. The apparatus of claim6, wherein the first gate is disposed so as to selectively controlingress and egress of workers between the deck and the first ladderextension.
 8. The apparatus of claim 1, further comprising a firstladder extension detachably connected to the upper flange of the firststringer and including a pair of longitudinally spaced apart sidebars,each sidebar configured to be pivotable between an extended position anda retracted position, wherein the retracted position disposes thesidebars so as to permit the gangway to bypass the first ladderextension when the gangway slides longitudinally along the firsttrackway.
 9. The apparatus of claim 8, wherein the first ladderextension includes a ladder rung connected between the pair of sidebarsand selectively deployable between an extended mode and a retractedmode, wherein in the extended mode the ladder rung is disposed fartheraway from the longitudinal centerline of the deck than is thedisposition of the first stringer.
 10. The apparatus of claim 8, whereinthe first ladder extension includes a ladder rung connected between thepair of sidebars and selectively deployable between an extended mode anda retracted mode, wherein in the retracted mode the ladder rung isdisposed close enough to the longitudinal centerline of the deck so asto allow the first gangway to bypass the ladder rung as the firstgangway moves slidably along the first trackway.
 11. The apparatus ofclaim 8, wherein the extended position of the sidebars of the firstladder extension disposes the sidebars relatively farther away from thelongitudinal centerline of the deck and the retracted position of thesidebars of the first ladder extension disposes the sidebars relativelycloser to the longitudinal centerline of the deck.
 12. The apparatus ofclaim 8, further comprising an emergency egress ladder extending beneaththe platform and disposed in alignment with the first ladder extension,the emergency egress ladder defining a plurality of rungs and includinga top rung disposed closest to the platform among the plurality ofrungs, the first ladder extension including a bottom ladder rungconnected between the pair of sidebars and selectively deployablebetween an extended mode and a retracted mode, wherein in the extendedmode the bottom ladder rung is disposed farther away from thelongitudinal centerline than in the retracted mode and in verticalalignment with the top rung of the emergency egress ladder.
 13. Theapparatus of claim 12, wherein the vertical distance separating theuppermost two rungs of the emergency egress ladder is substantially thesame as the vertical distance between the top rung of the emergencyegress ladder and the bottom rung of the ladder extension when theladder extension is disposed in the extended mode.
 14. The apparatus ofclaim 12, wherein the emergency egress ladder includes a pair of siderails spaced apart from each other and carrying the plurality of rungsand wherein when the ladder extension is deployed in an extended mode,the ladder extension assumes a configuration that acts as anuninterrupted extension of the emergency egress ladder, both as to theorientation of the sidebars with the side rails of the emergency ladderand the orientation of the ladder extension's bottom rung with the toprung of the emergency egress ladder.
 15. The apparatus of claim 1,further comprising a fall protection cage having an inboard endconnected to the outboard end of the gangway.
 16. The apparatus of claim1, further comprising a plurality of rigid legs disposed to support theplatform above the ground.
 17. An apparatus that provides worker fallprotection to an elevated platform having selectively deployable workeraccess to at least a portion of the top of a tank disposed above theground and carried by a railcar on a railroad track, the platformextending in a longitudinal direction and defined in part by a deckhaving a pair of longitudinally extending sides that are separated apartfrom one another in the transverse direction, each side of the deckbeing disposed to a respective opposite side of a virtual longitudinalcenterline that extends down the length of the platform and is orientednormal to the transverse direction, the apparatus comprising: a. a gatedetachably connectable along one of the longitudinally extending sidesof the platform, the gate including a gate post and a barrier pivotallyconnected to the gate post, wherein the gate post extends in a verticaldirection and has a vertically lower end defining a foot flange, thefoot flange defining at least one bolt opening; b. at least one bolthaving a threaded end; and c. at least one threaded nut; and d. whereinthe one bolt and the one nut are detachably connectable to each other soas to detachably connect the gate along one of the longitudinallyextending sides of the platform.
 18. The apparatus of claim 17, furthercomprising a ladder extension including a pair of longitudinally spacedapart sidebars, each sidebar configured to be pivotable between anextended position and a retracted position, wherein the ladder extensionincludes a first linkage and a second linkage, at least the firstlinkage having one end pivotally connected to a first one of thesidebars and a second end pivotally connected to the gate post, whereinpivoting movement of the sidebars with respect to the linkages rendersthe ladder extension selectively deployable between an extended mode anda retracted mode, wherein in the extended mode the sidebars of theladder extension are disposed spaced apart from the barrier by adistance substantially comparable to the length of the first linkage.19. A ladder extension apparatus that provides worker fall protection toan elevated platform having selectively deployable worker access to atleast a portion of the top of a tank disposed above the ground andcarried by a railcar on a railroad track, the platform extending in alongitudinal direction and defined in part by a deck having a pair oflongitudinally extending sides that are separated apart from one anotherin the transverse direction, each side of the deck being disposed to arespective opposite side of a virtual longitudinal centerline thatextends down the length of the platform and is oriented normal to thetransverse direction, the apparatus comprising: a. a gate detachablyconnectable along one of the longitudinally extending sides of theplatform, the gate including a gate post and a barrier pivotallyconnected to the gate post, wherein the gate post extends in a verticaldirection and has a vertically lower end defining a foot flange, thefoot flange defining at least one bolt opening; b. a pair oflongitudinally spaced apart sidebars, each sidebar configured to bepivotable between an extended position and a retracted position; c. afirst linkage and a second linkage, at least the first linkage havingone end pivotally connected to a first one of the sidebars and a secondend pivotally connected to the gate post, wherein pivoting movement ofthe sidebars with respect to the linkages renders the ladder extensionselectively deployable between an extended mode and a retracted mode,wherein in the extended mode the sidebars of the ladder extension aredisposed spaced apart from the barrier by a distance substantiallycomparable to the length of the first linkage; d. at least one bolthaving a threaded end; and e. at least one threaded nut; and f. whereinthe one bolt and the one nut are detachably connectable to each other soas to detachably connect the gate along one of the longitudinallyextending sides of the platform.